Baling press with prepress valves

Abstract

A baling press provided with a pressing box (2), a feed chute (1) connected with the pressing box via a passage, at least two prepress valves (5,6). The prepress valves (5,6) are each pivotable about a pivotal axis (7,8) provided with a flat wall (11,12) which in closed position closes off the passage from the feed chute (1) to the pressing box (2) and in opened position is disposed in the wall of the feed chute (1) and with a surface substantially curved about the corresponding pivotal axis, which surface in closed position bounds the feed chute in axial direction. One of the prepress valves (5,6) is provided with a connecting surface (13) which in the closed position is curved about a pivotal axis (8) of one other of the prepress valves. In that closed position, the connecting surface (13) is disposed at a distance from the curved surface (10) of said other prepress valve which is at most minor and substantially constant. The invention provides a possibility of avoiding material to be pressed getting stuck between the prepress valves when the prepress valves are being closed. <IMAGE>

I claim: 
     
       1. A baling press comprising a pressing box, a feed chute connected to the pressing box via a passage, and at least two prepress valves which are each pivotable about a pivotal axis between an open and a closed position, each prepress valve having a flat wall which in closed position closes off the passage from the feed chute to the pressing box and in opened position is disposed in the wall of the feed chute, and having a surface substantially curved around its corresponding pivotal axis, which surface in closed position closes off the passage from the feed chute to the pressing box, at least one of the prepress valves further having at least one connecting surface operatively connected and positioned between the curved surface and the flat wall which in closed position is curved around the pivotal axis of one other of the prepress valves and is adapted to the curved surface of the one other of the prepress valves, and in operation, the at least one prepress valve with the connecting surface is closed before the one other of the prepress valves is pivoted to a closed position, in such a way that in the closed position the connecting surface of the at least one prepress valve and the curved surface of the one other of the prepress valves are disposed at a mutual distance that is at most minor and substantially constant. 
     
     
       2. A baling press according to claim 1, provided with two oppositely disposed prepress valves, characterized in that the connecting surface is curved around the pivotal axis of the oppositely arranged prepress valve. 
     
     
       3. A baling press according to claim 2, characterized in that the connecting surface forms a concave cylinder sector. 
     
     
       4. A baling press according to claim 1, wherein in the closed position the distance between the connecting surface of the at least one prepress valve and the curved surface of the one other of the prepress valves is 20-50 mm. 
     
     
       5. A baling press according to claim 1, characterized by at least one screening plate mounted above at least one of said prepressing valves for hinging movement on an axis parallel to the pivotal axis, with the screening plate, when the prepress valve is in the opened position, connecting to the wall of said feed chute substantially in alignment therewith and extending at least beyond that edge of the flat wall of said prepress valve that is remote from the pivotal axis of the prepress valve and in the closed position being in contact with the curved surface of said prepress valve in a position pointing away from the feed chute.